hexagon: add GGML_HEXAGON_VTCM_SIZE (#31221)

* hexagon: add GGML_HEXAGON_VTCM_MB and GGML_HEXAGON_NTHREADS caps

Change-Id: Idffe1613c8db6f96aa842d43d1b2efaed45462a8

* hexagon: rename VTCM cap to GGML_HEXAGON_VTCM_SIZE, drop NTHREADS cap

Change-Id: If4c5b9ce9fd6b725c3561421c2295d40599d012d

* hexagon: make GGML_HEXAGON_VTCM_SIZE an override, accept K/M/G suffixes

Change-Id: Ib8eea84c22f24e6d986b37f215e504b046478c2c

docs/backend/snapdragon/README.md

@@ -324,6 +324,9 @@ on 4 physical NPUs, or `--devices 'HTP0[0-1:0],HTP1[0-1:1]'` on 2 physical NPUs
 - `GGML_HEXAGON_NHVX=0`
   Controls the number of HVX hardware threads to use. The default is all (actual number varies depending on the hardware version).
 
+- `GGML_HEXAGON_VTCM_SIZE=0`
+  Overrides the VTCM size used by each session. Accepts `K`, `M` and `G` suffixes; a plain number is in MB. The default (0) uses the size the hardware reports. Values above the hardware size will fail to start the session.
+
 - `GGML_HEXAGON_HOSTBUF=1` (default: 0, disabled)
   Enables allocating host buffers for debugging. By default, host buffers are disabled.
 

ggml/src/ggml-hexagon/ggml-hexagon.cpp

@@ -85,6 +85,7 @@ int    opt_arch       = 0; // autodetect
 size_t opt_ndev       = 1;
 size_t opt_nhvx       = 0; // use all
 int    opt_nhmx       = 1; // when set, enable HMX; when 0, use HVX only
+size_t opt_vtcm_size  = 0; // VTCM size override in bytes; 0 = auto-detect
 size_t opt_vmem       = HTP_OP_MAX_VMEM_DEFAULT;  // max available va space for buffer mappings
 int    opt_etm        = 0;
 int    opt_verbose    = 0;
@@ -2152,6 +2153,12 @@ void ggml_hexagon_session::allocate(const ggml_hexagon_device_config & config) n
             this->n_hvx     = this->n_threads;
             this->n_hmx     = (opt_nhmx != 0) ? (uint32_t)hw_n_hmx : 0;
             this->vtcm_size = (uint64_t)hw_vtcm_size;
+            if (opt_vtcm_size > 0) {
+                if (opt_vtcm_size > hw_vtcm_size) {
+                    GGML_LOG_WARN("ggml-hex: %s VTCM override %zu exceeds HW size %llu\n", this->c_name(), opt_vtcm_size, hw_vtcm_size);
+                }
+                this->vtcm_size = opt_vtcm_size;
+            }
             GGML_LOG_INFO("ggml-hex: %s hwinfo: threads %u, hvx %u, hmx %u, vtcm %llu MB\n",
                           this->c_name(), this->n_threads, this->n_hvx, this->n_hmx,
                           (unsigned long long)(this->vtcm_size / (1024 * 1024)));
@@ -2161,7 +2168,7 @@ void ggml_hexagon_session::allocate(const ggml_hexagon_device_config & config) n
             this->n_threads = opt_nhvx > 0 ? (uint32_t) (std::min)(opt_nhvx, (size_t) HTP_MAX_NTHREADS) : default_n_threads;
             this->n_hvx     = this->n_threads;
             this->n_hmx     = (opt_nhmx != 0) ? 1 : 0;
-            this->vtcm_size = 8 * 1024 * 1024;
+            this->vtcm_size = opt_vtcm_size > 0 ? opt_vtcm_size : 8 * 1024 * 1024;
         }
     }
 
@@ -2230,7 +2237,8 @@ void ggml_hexagon_session::allocate(const ggml_hexagon_device_config & config) n
     this->op_batch = new ggml_hexagon_opbatch(this, opt_opbatch, this->max_vmem);
 
     // Start dspqueue/opbatch processing
-    err = htp_iface_start(this->handle, this->session_id, this->queue_id, this->n_threads, opt_nhmx, this->max_vmem, (uint32_t) opt_power_mode);
+    err = htp_iface_start(this->handle, this->session_id, this->queue_id, this->n_threads, opt_nhmx, opt_vtcm_size, this->max_vmem,
+                          (uint32_t) opt_power_mode);
     if (err != 0) {
         GGML_LOG_ERROR("ggml-hex: %s failed to start session: 0x%08x\n", this->c_name(), (unsigned) err);
         throw std::runtime_error("ggml-hex: iface start failed (see log for details)");
@@ -3391,6 +3399,7 @@ static void ggml_hexagon_init(ggml_backend_reg * reg) {
     const char * str_etm      = getenv("GGML_HEXAGON_ETM");
     const char * str_nhvx     = getenv("GGML_HEXAGON_NHVX");
     const char * str_nhmx     = getenv("GGML_HEXAGON_NHMX");
+    const char * str_vtcm_size = getenv("GGML_HEXAGON_VTCM_SIZE");
     const char * str_mm_select = getenv("GGML_HEXAGON_MM_SELECT");
     const char * str_fa_select = getenv("GGML_HEXAGON_FA_SELECT");
     const char * str_fa_split  = getenv("GGML_HEXAGON_FA_SPLIT");
@@ -3456,6 +3465,7 @@ static void ggml_hexagon_init(ggml_backend_reg * reg) {
     }
     opt_nhvx      = str_nhvx     ? strtoul(str_nhvx, NULL, 0)             : opt_nhvx;
     opt_nhmx      = str_nhmx     ? atoi(str_nhmx)                         : opt_nhmx;
+    opt_vtcm_size = str_vtcm_size ? parse_size(str_vtcm_size)                 : opt_vtcm_size;
     opt_mm_select = str_mm_select ? atoi(str_mm_select)                   : opt_mm_select;
     opt_fa_select = str_fa_select ? atoi(str_fa_select)                   : opt_fa_select;
     opt_fa_split  = str_fa_split  ? atoi(str_fa_split)                   : opt_fa_split;

ggml/src/ggml-hexagon/htp/htp_iface.idl

@@ -11,7 +11,7 @@ struct htp_iface_pmu_conf {
 };
 
 interface htp_iface : remote_handle64 {
-    AEEResult start(in uint32 sess_id, in uint64 dsp_queue_id, in uint32 n_hvx, in uint32 n_hmx, in uint64 max_vmem, in uint32 power_mode);
+    AEEResult start(in uint32 sess_id, in uint64 dsp_queue_id, in uint32 n_hvx, in uint32 n_hmx, in uint64 vtcm_size, in uint64 max_vmem, in uint32 power_mode);
     AEEResult stop();
     AEEResult mmap(in uint32 fd, in uint64 size);
     AEEResult munmap(in uint32 fd);

ggml/src/ggml-hexagon/htp/main.c

@@ -325,8 +325,11 @@ static unsigned int vtcm_query_size(void) {
     return vtcm_size;
 }
 
-static int vtcm_alloc(struct htp_context * ctx) {
+static int vtcm_alloc(struct htp_context * ctx, uint64_t size_override) {
     unsigned int vtcm_size = vtcm_query_size();
+    if (size_override) {
+        vtcm_size = (unsigned int) size_override;
+    }
 
     compute_res_attr_t attr;
     HAP_compute_res_attr_init(&attr);
@@ -438,7 +441,7 @@ static const struct htp_power_profile htp_power_profiles[HTP_POWER_MODE_COUNT] =
 
 #undef HTP_POWER_PROFILE_ENTRY
 
-AEEResult htp_iface_start(remote_handle64 handle, uint32_t sess_id, uint64_t dsp_queue_id, uint32_t n_hvx, uint32_t n_hmx, uint64_t max_vmem, uint32_t power_mode) {
+AEEResult htp_iface_start(remote_handle64 handle, uint32_t sess_id, uint64_t dsp_queue_id, uint32_t n_hvx, uint32_t n_hmx, uint64_t vtcm_size, uint64_t max_vmem, uint32_t power_mode) {
     struct htp_handle * h = (struct htp_handle *) handle;
     if (!h) {
         return AEE_EBADPARM;
@@ -557,7 +560,7 @@ AEEResult htp_iface_start(remote_handle64 handle, uint32_t sess_id, uint64_t dsp
     ctx->max_vmem    = max_vmem;
     ctx->dsp_queue   = dsp_queue;
 
-    err = vtcm_alloc(ctx);
+    err = vtcm_alloc(ctx, vtcm_size);
     if (err != AEE_SUCCESS) {
         FARF(ERROR, "Unable to allocate VTCM");
         htp_iface_stop(handle);